Safety lowering and control mechanism for winches and the like



Dec. 11, 1945. c.-c. MARTIN 2,

SAFETY LOWERING AND CONTROL MECHANISM FOR WINCHES AND THE LIKE Filed Aug. 1, 1944. 2 Sheets-Sheet 1 W HuvWh/V, ATTORNEYS? c. c. MARTIN 2,390,891

SAFETY LOWERING AND CONTROL MECHANISM FOR WIiICHES AND THE LIKE I Dec. 11, 1945.

2 Sheets-Sheet 2 Filed Aug. 1, 1944 INVENTOR.

ATTORNEYS.

Patented Dec. 11, 1945 SAFETY LOWERING AND CONTROL MECHA- NISM FOR WINCHES AND THE LIKE Charles C. Martin, Cleveland Heights, Ohio, as-

signor to David Round & Son, Garfield Heights,

Ohio, a firm v Application August 1, 1944, Serial No. 547,577

3 Claims. (Cl. 254-186) This invention as indicated relates to a safety lowering and control mechanism for winches and the like. More particularly, it comprises an automatically acting mechanism which permits progressive releasing or lowering action under full control of the operator.

In operating winches the lowering movement usually involves separate braking mechanism which is subject to excessive wear with possibility of complete failure, or at least overrunning with heavy damage or injury to the load or operatives. In the present invention the load automatically applies the braking or checking force and the operative sets the rate of control or braking action. This is preferably accomplished by the same means used in manually lifting the load, the reversing of the motion of the hand-crank controlling both the degree of lowering movement and the speed with which it takes place.

The principal object of the present invention is to provide a safety lowering and control mechanism for winches and the like.

Another object of the invention is to provide a single lifting and lowering mechanism for Winches and the like which will be dependable in action and of long service life.

Another object of the invention is to provide an improved winch structure particularly suited for manual operation which will at all times be under control during both the hoisting and lowering operation.

Another object of the invention is to provide a winch with load-actuated braking means of small size and high capacity responsive to releasing control of the operator with unusual precision and yet' operating smoothly and without shock.

Other and further objects of the invention will appear in the course of the following description.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but several of various forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is an enlarged central vertical sectional view showing the operative features of the invention, with associated parts shown in full lines, as seen along the line l-l shown in Figure 2;

Fig. 2 is a fragmentary end elevation of a portion of the structure shown in Figure 1;

Fig. 3 is an end elevation of a winch structure provided with a safety lowering and control mechanism embodying the features of the invention; and

Fig. 4 is an elevation of the winch structure as seen from the right-hand side of Figure 3.

The safety lowering and control mechanism as applied to a manually operated winch comprises a unit I associated with a pinion 2 adapted to be engaged with a gear 3, or gear train, of a winch or similar structure. The pinion 2 is carried on a shaft 4 having its free end 5 engaged in a suitable bearing on the winch frame and held therein by a latch element rotatably engaging the annular recess 6, The opposite end 1 of the shaft 4 is of reduced diameter and provided with a keyway 8 by means of which a tubular hub 9 formed integrally with a braking disc I I, is non-rotatably held on said shaft by a suitable key engaging said keyway. The tubular hub 9 is provided with a heavy duty right-hand screw-thread l2 engaging in a screw-threaded opening 13 in the hub M of a movable brake-actuating member l5.

The brake-actuating member l5 has a range of endwise movement provided by said screw-threaded engagement on the tubular hub 9. It is held from disengagement from the hub 9 in one direction by the abutment plate I6 held by a castellated nut l1 on the reduced screw-threaded end l8 of the shaft 4, which is locked by a cotter pin I9.

The inner face of the braking disc I I provides a surface against which an annular friction member 2| is engaged, said friction member being housed in a recess in the adjacent face of a floating braking disc 22, having a rearwardly-projecting tubular hub 23 rotatably engaged over a re duced terminal portion 24 of the endwise movable brake-actuating member IS. The hub 23 engages a circular recess 26 formed in the adjacent end face of the disc portion 21 of the brake-actuating member I 5.

The disc 21 abuts the floating braking disc 22 through a perforated brass free friction annular member 28 interposed between said adjacent disc surfaces and pivotally supported on the thin extension flange 25.

The floating braking disc 22 is provided on its outer circumference with an overhanging flange 3| formed with ratchet teeth 32, engageable by a spring pressed pawl 33 pivotally mounted on the adjacent winch frame 34.

A recessed cap member 35 is bolted to spokes 36 on the brake-actuating member I 5 and engages in spaced relation over the abutment plate l6 and nut l'l. The cap member carries centrally of its end face an integral stub shaft 31 over which the hub portion 38 of the hand-crank 39 may be engaged. For movement of the winch without a load the hand-crank 39 may be engaged on the main shaft M of the large gear 3.

For extra heavy duty the lowering and control unit 42 which is substantially identical in its operative elements with unit I may drive the drum 43 of hand winch '44 through a series of reduction gears 45 as shown in Figures 3 and 4. It will be noted that the pawl 46 is applied to a member 1,

ber l on its screw-threaded support and press the disc 21 against the annular friction member 28. which bears againstthe floating braking disc 22 forcing it into compressive engagement'with the friction member 2| pressing on the fixed braking disc, ll keyed to the 'pinionshaft 4. The pinion is in driving engagement with the drum of the winch and hoisting action takes place.

To bring about. lowering movement of the load the crank handle 39 is moved reversely. This re-:

lieves the pressure of the brake-actuating mem-,

ber, moving transversely on'its screw-threaded support, on the floating braking disc 22 which is held from rotation counter-clockwise by the pawl 33, and all the friction elements move outward- 1y away from the shaft supported braking disc I I:.

As the braking disc I I. turns counter-clockwise with the pinion shaft the load; will be lowered,

- but the lowering operation turns the tubular hub- 9 with itsscrew-thread t2 whichmovement tends to draw the friction elements of the unit into braking engagement. However, continued movement of the screw-threaded member 13 t releasing position again tends to. separate the friction elements, and so longastherateof separating movement of the outer screw-threaded elemerit of the pair'exceeds the. rateof movementof its companion inner screw-threaded element there will be no reengagement of the, friction elements and the load will continue to. be lowered. By controlling these members so as to bring about partial frictional engagement the lowering rate canbe controlled with a high degree of precision.

Other modes of applying the principlev of my invention may be employed, instead ofthose ex:- plained, change being made; as regards thev mechanism herein disclosed, provided the mean stated by any of .the following claims or the equivalent of such stated means be employed,

I therefore particularly point out and distinctly claim as my invention:

1. In an apparatus of the character described a frame, a drum rotatably supported on said frame, a load carrying cable engaged over such drum, a power multiplying mechanism associated with said drum for actuating the same and ele- V vating the load on said cable when moved in one direction of rotation, comprising a pinion iirryinga disk and ascrew shaft, a cranl-i operated clamping member movably' mounted on said screw shaft and provided with an extension hub,

a ratchet disk rotatably mounted on the hub of said movable clamping member intermediate the same and said disk, a pawl pivotally mounted on said frame in operative relation to said ratchet disk, a hub bearing provided on said ratchet disk, a free perforated friction disk mounted on said hub bearing, said clamping member adapted to move said parts. into engagement for elevating the load for lowering said load under frictional braking control at a speed proportional to the movement of said power multiplying mechanism through rotation in the reverse direction.

2. A winch, comprisinga frame, a drum rotatably supported: in-said frame, gear and. pinion means for driving said drum, a braking disk and screw threaded member operatively connected with said pini0n,, a screw threaded sleeve having an extension hub and a clamping disk mounted on said screw threadedmember, a hol-low'housing' engaging over said screw threaded member and connected with said screw threaded sleeve for operating the same, a crank arm releasably mounted on a projection of said hollow housing.

a ratchet disk rotatably mounted on said hub. intermediate. said braking disk and clamping disk, and a pawl pivotally mounted on said supporting frame for operatively engaging said ratchet disk.

3; A winch comprising: spaced: apart base supported frames, a drum. journaied between said frames, a driving gear outsidev of one of said frames operatively connected to said drum for actuating the same, a. safety lowering and control mechanism associated with said gear and frame comprising a shaft journaled" in said one frame and having an integral pinion engaging said gear, a braking disk havinga; longitudinally extending screw threaded hub-fixed on said shaft, a clamping member mounted on said hub havingcomplementary screw threads for engaging with the screw thread of said hub, a floating braking disk between said braking disk and clampingmember, said clamping member having an annular extending bearing portion forjournali'ng said floating braking disk, said floating braking disk being provided with ratchet teeth on itscircumference, a pawl pivotally; mounted on said one frame for engaging said ratchet teeth,, a housing on said clamping member for enclosing one end of said shaft and being provided with. a projection forreleasably mountinga. hand crank.

.CHARLES C. MARTIN. 

